Supported arene complex olefin catalysis

ABSTRACT

A transition metal compound containing at least one π-bonded arene is contacted with an inorganic oxide, hydroxide, oxyhalide, hydroxyhalide or halide. The transition metal compound can be a compound such as titanium(O)ditoluene or TiCl 2 .2AlCl 3  durene. The inorganic compound is preferably of high surface area and this may be inherent in the compound or can be achieved by a grinding procedure. The inorganic compound can be treated with a halogen containing compound either before, during or after the contacting with the transition metal compound. The product of the contacting is useful either as catalyst for the polymerization of unsaturated hydrocarbon monomers or as a component of such a catalyst. When used as a component of an olefine polymerization catalyst, the transition metal product can be mixed with an organo-aluminum compound and a Lewis Base compound such as an ester. The catalysts can be used to polymerize or copolymerize olefine monomers to obtain a high yield of a polymer having good properties. Some of the catalysts produce polymers of high molecular weight which have an interesting combination of properties.

This is a division, of application Ser. No. 744,827 filed Nov. 24, 1976,U.S. Pat. No. 4,121,030, Oct. 17, 1978.

The present invention relates to the treatment of compounds oftransition metals and to the use of the treated compounds as catalysts,or components of catalysts, for the polymerization of ethylenicallyunsaturated hydrocarbon monomers.

According to the present invention there is provided a process for thetreatment of compounds of transition metals wherein a compound of atransition metal of Groups IVA or VA of the Periodic Table, whichcompound contains at least one π-bonded arene group, is contacted with aparticulate inorganic compound which is (A) an inorganic oxide, aninorganic hydroxide, an inorganic oxyhalide, an inorganic hydroxyhalideor an inorganic halide; (B) a mixture of at least two compounds from A;or (C) a compound obtained by the reaction of at least two compoundsfrom A.

The transition metal compound is contacted with the inorganic compoundin proportions such that from 0.05 up to 50% by weight of the transitionmetal compound is used relative to the inorganic compound. Typically theamount of the transition metal compound is such as to provide from 0.5up to 20% by weight of the transition metal compound relative to theinorganic compound.

The transition metal is preferably a metal of Group IVA and isparticularly titanium. The transition metal compound may contain onlythe π-bonded arene group or groups, or may also contain other groupingssuch as halogen atoms, and the compound may be in the form of a complexwith other compounds. In the transition metal compound the valency ofthe metal may be zero or any valency wherein the transition metal isable to form a stable compound containing at least one π-bonded arenegroup. Suitable transition metal compounds include for exampletitanium(O)ditoluene or a titanium dichloride-aluminium chloride-arenecomplex where the arene group is any suitable arene for example durene(1,2,4,5-tetramethylbenzene). The term "arene" as used herein is used tomean a compound containing a six-membered hydrocarbyl ring which ringcontains a completely delocalized double bond system. It will beappreciated that the term arene is used to include benzene, toluene,xylene, durene, hexamethylbenzene and substituted derivatives thereofsuch as chlorobenzene.

The inorganic compound preferably has a high surface area and it will beappreciated that some compounds of this type inherently have such a highsurface area whereas with other compounds it is necessary to grind orotherwise comminute the inorganic compound in order to achieve asatisfactorily high surface area. It is preferred that the surface areaof the inorganic compound is at least 1 m² /g and it is particularlypreferred that the area is at least 10 m² /g and especially 30 m² /g.Suitable inorganic compounds include alumina, mixtures of alumina andsilica, the mixed oxide of aluminum and silicon, magnesium dihalide andmanganese dihalide, and, in the case of the latter two compounds, inorder to achieve a high surface area it is desirable that they besubjected to a grinding operation. If the inorganic compound is to beground to achieve a high surface area, the grinding can be effectedbefore or after contacting with the transition metal compound or thecontacting can be effected during the grinding operation.

Before, during or after the contacting of the inorganic compound withthe transition metal compound, the inorganic compound may also betreated with a halogen-containing compound which may be either anorganic or inorganic compound. Suitable halogen-containing compoundsinclude hydrogen chloride, titanium tetrachloride and toluoyl chloride.The amount of the halogen-containing compound which is used ispreferably at least 0.10 moles per g atom of transition metal which ispresent in the transition metal compound, and is very preferably atleast 0.5 moles per g atom of the transition metal compound. Veryconveniently a molar excess of the halogen-containing compound is usedand any excess of the halogen-containing compound which remains aftercompletion of the treatment may be removed using any suitable techniquesuch as filtration and/or washing with an inert liquid.

In addition to, or as an alternative to, the treatment with thehalogen-containing compound, the inorganic compound may be treated withan organic Lewis Base, which organic Lewis Base could be presentcomplexed with the transition metal compound. A wide range of organicLewis Base compounds have been proposed for use as components of Zieglercatalyst systems, and any such compounds may be used. Thus, theorgano-Lewis Base compound may be an ether, an ester, a ketone, analcohol, a sulphur-containing analogue of ethers, esters, ketones andalcohols, an organo-silicon compound, an amide, urea or thiourea, analkanolamine, an amine, a cyclic amine, a diamine or anorgano-phosphorus compound such as an organo-phosphine, anorgano-phosphine oxide, an organo-phosphite or organo-phosphate. The useof organo-Lewis Base compounds is disclosed inter alia in British PatentSpecifications Nos. 803,198, 809,717, 880,998, 896,509, 920,118,921,954, 933,236, 940,125, 966,025, 969,074, 971,248, 1,013,363,1,017,977, 1,049,723, 1,122,010, 1,150,845, 1,208,815, 1,234,657,1,324,173, 1,359,328 and 1,383,207, Belgian Patent Specification No. 693551 and published German Patent Application No. 2 329 723. If anorgano-Lewis Base compound is included in the system, the proportion ofthe organo-Lewis Base compound is preferably at least 0.1 moles per gatom of the transition metal which is present in the transition metalcompound, very preferably not more than 5 moles, and especially not morethan one mole, of the Lewis Base compound per g atom of transitionmetal.

The contacting of the transition metal compound with the inorganiccompound is conveniently effected by contacting the inorganic compoundwith a solution of the transition metal compound in a hydrocarbon orother inert diluent. The contacting may be effected by stirring asuspension of the inorganic compound in a suitable inert diluent with asolution of the transition metal compound, or may be effected bygrinding the inorganic compound in the presence of the transition metalcompound, which may, if desired, be in solution in a suitable inertliquid. However, the inorganic compound may be subjected to a grindingstep either before or after it has been contacted with the transitionmetal compound, and it is not necessary to effect grinding of theinorganic compound in the presence of the transition metal compound.

The contacting of the transition metal compound with the inorganiccompound may be effected at any suitable temperature but it is preferredto use temperatures of ambient temperature or below, particularly whenusing compounds such as titanium(O)ditoluene which are thermallyunstable. The solvent used for the dissolution of the transition metalcompound may be any suitable inert liquid and is conveniently anaromatic liquid since many of the transition metal compounds have agreater solubility in such diluents. If the inorganic compound issubjected to a grinding step, this can be effected in any known mannerfor example in a rotating ball mill or in a vibrating ball mill. Thetime of grinding will be dependent on a number of factors including thenature of the material to be ground, the particle size desired in theground product and the intensity of the grinding. In general a time offrom 1 hour up to 100 hours is sufficient to effect the requisitecomminution of the inorganic material. The milling can be effected atany desired temperature but in general it is preferred that the grindingis effected at ambient temperature or below particularly if the grindingis being effected in the presence of a thermally unstable transitionmetal compound.

Although some of the transition metal compounds are thermally unstableand have to be stored at low temperature, for exampletitanium(O)ditoluene has to be stored at about -78° C., the product ofcontacting the transition metal compound with the inorganic compound hasimproved stability and can be stored at ambient temperature withoutappreciable deterioration. Thus the product of contacting the transitionmetal compound with the inorganic compound can be stored as a dry solidor as a suspension in a suitable inert liquid and we have found that,even when stored as a suspension for a week or more, the product stillpossesses considerable activity as a catalyst, or a component of acatalyst, for the polymerization of ethylenically unsaturatedhydrocarbon monomers.

The product of contacting the transition metal compound with theinorganic compound can be used, either alone or together with othercompounds such as the organic compound of a non-transition metal ofGroups IA and IIA or of aluminum, to polymerize ethylenicallyunsaturated hydrocarbon monomers.

Thus, as a further aspect of the present invention there is provided acatalyst suitable for the polymerization of ethylenically unsaturatedhydrocarbon monomers, which catalyst contains a transition metalcomponent which is the product of contacting a transition metal compoundof a metal of Groups IVA or VA of the Periodic Table, which compoundcontains at least one π-bonded arene, with an inorganic compound whichis (A) an inorganic oxide, an inorganic hydroxide, an inorganicoxyhalide, an inorganic hydroxyhalide or an inorganic halide, (B) amixture of at least two compounds from A; or (C) a compound obtained bythe reaction of at least two compounds from A.

The catalyst may be a single component catalyst system which consistssolely of the transition metal component but the catalyst may include,as a second component, at least one organo-metallic compound of aluminumor of a non-transition metal of Group IIA of the Periodic Table or acomplex of an organo-metallic compound of a non-transition metal ofGroup IA or IIA of the Periodic Table and an organo-aluminum compound.

The second component of the catalyst system can be a Grignard reagentwhich is substantially ether free or a compound of the type Mg(C₆ H₅)₂.Alternatively, the second component can be a complex of anorgano-metallic compound of a non-transition metal of Groups IA or IIAwith an organo-aluminum compound for example Mg[Al(C₂ H₅)₄ ]₂ or lithiumaluminum tetraalkyl. It is preferred that the second component is anorgano-aluminum compound such as a bis(dialkyl aluminum)oxyalkane, abis(dialkyl aluminum)oxide, an aluminum hydrocarbyl sulphate, analuminum hydrocarbyloxyhydrocarbyl or particularly an aluminumtrihydrocarbyl or dihydrocarbyl aluminum halide or hydride. Weparticularly prefer to use either an aluminum trialkyl such as aluminumtriethyl or an aluminum dialkyl halide such as diethyl aluminumchloride. We particularly prefer that the second component is ahalogen-free material for example an aluminum trialkyl.

In addition to the first and second components, the catalyst may alsocontain other components for example organo-Lewis Base compounds. Theorgano-Lewis Base compound may be the same as, or different from, theorgano-Lewis Base compound with which the inorganic compound and thetransition metal compound are optionally treated. Thus the organic LewisBase compound which may be used as a possible third component of thecatalyst may be any Lewis Base compound of the type previouslydescribed. The Lewis Base compound may be incorporated in to thecatalyst system as a complex with the organo-metallic component of thecatalyst. Suitable complexes of the organo-Lewis Base compound and theorgano-metallic compound include complexes of aluminum trialkyl withesters and in particular with aromatic esters such as ethyl benzoate orethyl anisate.

In addition to or instead of the Lewis Base compound the catalyst mayalso contain a substituted or unsubstituted polyene. The polyene may bean acyclic polyene such as 3-methylheptatriene-1,4,6 or a cyclic polyenesuch as cyclooctatriene, cyclooctatetraene or cycloheptatriene or may bea derivative of such cyclic polyenes for example the alkyl- oralkoxy-substituted polyenes, tropylium salts or complexes, tropolone ortropone.

The proportions of the catalyst components can be varied quite widelydepending on the particular materials used and the absoluteconcentrations of the components. The proportions will also be dependenton the monomer which is to be polymerized. However, if the catalystsystem includes components in addition to the transition metalcomponent, then these may be present in the conventional proportions forZiegler catalyst systems. More specifically, for each gram atom of thetransition metal which is present in the product of contacting thetransition metal compound with the inorganic compound, there should bepresent at least 0.05 and preferably at least 1 mole of theorgano-metallic compound which is the second component of the catalyst.However, in general it is preferred to use larger quantities of theorgano-metallic component and the proportion of this compound may be ashigh as 100 moles for each gram atom of the transition metal compound,although we prefer to use smaller proportions of the organo-metalliccompounds, for example not more than 25, and particularly not more than10 moles, of the second component for each gram atom of the transitionmetal. If a Lewis Base component is also present in the catalyst system,the number of moles of the Lewis Base compound should not be greaterthan the number of moles of the organo-metallic compound which is thesecond component of the catalyst. If the catalyst includes a polyene,then the molar proportion of the polyene is preferably less than themolar proportion of the second component. Preferably for each mole ofthe second component there is present from 0.05 up to 0.5 particularlyfrom 0.1 up to 0.2 moles of the polyene.

The catalyst of the present invention can be used to polymerizeethylenically unsaturated hydrocarbon monomers by contacting at leastone such monomer with a catalyst of the type hereinbefore described.

More specifically there is provided a process for the production of ahydrocarbon polymer wherein at least one ethylenically unsaturatedhydrocarbon monomer is contacted with a polymerization catalyst of thetype hereinbefore described.

The ethylenically unsaturated hydrocarbon monomer may be a mono-olefineand may be any which is capable of being polymerized using a Zieglercatalyst system. Thus monomers which can be polymerized by the processof the present invention may be mono-olefines containing up to 18 carbonatoms, for example butene-1 and 4-methylpentene-1 and particularlyethylene and propylene. If desired the olefines, particularly ethyleneand propylene, may be copolymerized together for example using asequential polymerization technique such as is described in BritishPatent Specifications Nos. 970,478, 970,479 and 1,014,944. The monomermay, alternatively, be a diene or polyene such as, for example,butadiene.

The polymer product obtained is affected by the nature of the catalystsystem and, in particular, appears to be influenced by the nature of thecatalyst support. Thus, if the support is an oxide, particularly onecontaining alumina, the catalyst preferably consists of the supportedπ-arene compound only. We have obtained high yields of polyethylene byeffecting the polymerization of ethylene, using as the catalyst,titanium(O)ditoluene supported on alumina. The polyethylene thusobtained has a high molecular weight as indicated by the fact that themelt flow index (measured at 190° C. using a 2.16 kg weight) isessentially zero.

Surprisingly we have found that propylene can be polymerized to give asolid polymeric product using a π-arene compound supported on an oxideas the sole catalyst. The product obtained has a combination ofproperties which are believed to be unique.

More specifically there is provided a solid propylene polymer having amelt flow index of not greater than 0.02 (measured at 190° C. using a 10kg weight), and at least 3 head-to-head units for each 100 propyleneunits.

The polymer typically has a melt flow index of less than 0.01 at 190° C.and 10 kg.

The number of head-to-head units in the solid polymer is typically about4 for each 100 propylene units and does not exceed about 6 for each 100propylene units. By "head-to-head units" is meant a structure of thetype

    --CH(CH.sub.3)--CH(CH.sub.3)--

in the polymer chain. It will be appreciated that in commerciallyavailable propylene polymers, the structure is essentially all of the"head-to-tail" type, that is

    --CH(CH.sub.3)--CH.sub.2 --CH(CH.sub.3)--CH.sub.2 --

The presence of head-to-head units in a structure of the type

    --CH(CH.sub.3)--CH.sub.2 --CH(CH.sub.3)--CH(CH.sub.3)--CH.sub.2 --CH.sub.2 --CH(CH.sub.3)--

has been established by carbon-13 nuclear magnetic resonance (¹³ Cnmr)and infrared spectroscopy (an absorption band at 752 cm⁻¹).

The polymer is substantially isotactic, as determined by ¹³ Cnmr andproton magnetic resonance (pmr), and has an isotactic content of atleast 70%, typically about 80%, as determined from the triads which aremm centered.

The polymer contains at least 5% of racemic diads, as measured by pmr.The percentage of racemic diads does not, in general, exceed 15% and istypically about 9 to 12%.

The polymer has some elastomeric properties and elongations of at least1000% have been achieved. On removal of the stress, the test specimenshowed partial recovery to about 200% elongation.

The polymer has a low glass transition temperature (measured using atorsional pendulum) which is below 0° C. and typically between -20° and-10° C.

The polymer has a low temperature brittle point which can be below -20°C., for example -26° C.

The polymer is conveniently obtained by polymerizing propylene at atemperature of at least 40° C. in the presence of a catalyst which isthe product of contacting a compound of a transition metal of Groups IVAor VA of the Periodic Table, which compound contains at least oneπ-bonded arene group, with an inorganic oxide which is, or whichcontains, aluminum oxide.

Whilst the catalyst system can include a conventional organo-metalliccompound of a non-transition metal such as aluminum, since the presenceof such compounds has no significantly useful effect, we prefer to usethe supported transition metal compound as the only catalyst component.The polymerization process is conveniently effected in an inerthydrocarbon diluent and may be effected in the presence of hydrogen. Asmall proportion (not more than about 5% of the total polymer yield) ofa diluent soluble polymer is formed, and this polymer hascharacteristics which are similar to those of the insoluble, solidpolymer but has a lower proportion of isotactic polymer and a largerproportion of head-to-head units.

In contrast to the behaviour of the catalyst systems supported oninorganic oxides, those supported on inorganic halides, such asmagnesium chloride, polymerize olefin monomers to high, but not ultrahigh, molecular weight products. Using catalyst systems supported oninorganic halides, it is preferred that the catalyst system includes asecond component which is an organo-metallic compound of aluminum or ofa non-transition metal of Group IIA of the Periodic Table, or a complexof a non-transition metal of Group IA or IIA of the Periodic Table andan organo-aluminum compound. For the polymerization of propylene andhigher olefines, it is particularly preferred that such catalyst systemsalso include an organo-Lewis Base compound.

We have found that the process of the present invention can be used toobtain a high yield of a polymer relative to the amount of the catalystused. If the polymer being polymerized is propylene, or a higherolefine, then, if the preferred catalyst systems are used, a relativelylow proportion of the undesirable soluble polymer may also be obtained.For the polymerization of propylene and higher olefines, particularlygood results have been obtained using a transition metal component whichis a product of contacting the transition metal compound, for exampletitanium(O)ditoluene, with the inorganic compound, especially magnesiumchloride, and treating the inorganic compound either before, during orafter the contacting with the transition metal compound with ahalogen-containing material for example toluoyl chloride, and effectingpolymerization in the presence of an aluminum trihydrocarbyl compound,such as aluminum triethyl and an ester such as ethyl anisate.

It is well known that many catalysts which can be used to polymerizeethylenically unsaturated monomers are susceptible to the effects ofimpurities and the activity and stereospecificity of such catalysts canbe affected in a detrimental manner by the presence of small quantitiesof impurities, particularly oxygen and polar compounds such as water andalcohol. Thus at all stages in the preparation and use of the productsof the present invention, the materials should preferably be handled inan inert atmosphere which is substantially free of oxygen andoxygen-containing impurities. Similarly, the monomers (and diluents, ifany) should also be substantially free of oxygen and oxygen-containingimpurities. However, catalysts in accordance with the present inventioncan be used in smaller proportions than the conventional Ziegler typecatalyst and accordingly are more susceptible to any impurities presentin the system. Thus, for use with the catalyst of the present invention,it is desirable that the monomers and any diluents which are ofcommercial purity are subjected to a further purification procedure. Itis preferred to use a monomer containing less than 1 ppm by volume ofwater and less than 0.5 ppm by volume of oxygen, and a diluentcontaining less than 10 ppm by weight of each of water and oxygen.

Any suitable purification treatment can be used and the treatment can beeffected in more than one stage if desired. The particular purificationtreatment used will be dependent on the purity of the startingmaterials.

Satisfactory purity can be achieved in most cases by passing the monomer(and diluent, if used) through a bed of a material which is capable ofabsorbing the impurities contained in the monomer or diluent, forexample as described in British Patent Specifications Nos. 1,111,493 and1,226,659.

Using catalysts in accordance with the present invention, polymerizationcan be carried out in the presence or absence of an inert diluent suchas a suitably purified paraffinic hydrocarbon. If a diluent is not used,polymerization can be effected in the liquid phase using excess liquidmonomer as the suspension medium for catalyst and polymer product. Ifthe monomer is used in the gaseous phase, polymerization can be effectedusing any technique suitable for effecting a gas/solid reaction such asa fluidized bed reactor system or a ribbon blender type of reactor.

Polymerization may be effected either in a batch manner or on acontinuous basis. The catalyst components may be introduced into thepolymerization vessel separately but it may be preferred, particularlyif polymerization is being effected on a continuous basis, to mix allthe catalyst components together before they are introduced into thepolymerization reactor. Alternatively, a proportion of the catalyst maybe added to initiate polymerization and further quantities of one ormore of the catalyst components are added at one or more times duringthe polymerization. Conveniently at least 25% of each catalyst componentis added to initiate polymerization, the remaining catalyst componentsbeing added during the polymerization. The reaction product of thetransition metal compound and the inorganic compound is a solid materialand since feeding a slurry of this solid material may be inconvenient,it may be preferred that all of the said reaction product is added,together with some of each of the other catalyst components, to initiatepolymerization and the rest of the other catalyst components are addedduring the polymerization. It is desirable that in any mixing of thecatalyst components the transition metal-containing component is notallowed to come into contact with any organo-Lewis Base compound whichis present as the third component in the absence of the organo-metalliccompound which is the second component of the catalyst.

The polymerization can be effected in the presence of a chain transferagent such as hydrogen or a zinc dialkyl, in order to control themolecular weight of the product formed. If hydrogen is used as the chaintransfer agent it is conveniently used in an amount of from 0.01 up to5.0%, particularly from 0.10 up to 2.0% molar relative to the monomer.The amount of chain transfer agent will be dependent on thepolymerization conditions, including the catalyst system and especiallythe temperature which is typically in the range from 20° up to 100° C.,preferably from 50° up to 80° C. It will be appreciated that somecontrol of the molecular weight of the product formed can be achieved byvariation in the polymerization temperature.

Using catalysts in accordance with the present invention particularlytwo or more component catalysts wherein the transition metal componenthas been obtained by contacting the transition metal compound with theinorganic compound and also treating the inorganic compound with ahalogen containing material, we have been able to polymerize propyleneto obtain a high yield of polymer which has a high flexural modulus.Thus when using a catalyst containing a titanium compound, after onlyone hour of polymerization, we have obtained a propylene polymer havingless than 50 parts per million by weight of titanium from the residualcatalyst and having a flexural modulus of at least 1.00 GN/m². Theflexural modulus of the polymer is the modulus as measured by theapparatus as described in Polymer Age, March 1970, pages 57 and 58 at 1%skin strain after 60 seconds at 23° C. and 50% relative humidity usingtest sample as prepared in Examples 13 to 19.

The transition metal content of the polymer may be determined by anysuitable analytical technique for example X-ray fluoroescencespectrometry.

Propylene homopolymers prepared by the process of the present inventionmay have a residual transition metal content, particularly a residualtitanium content of about 10 to 20 parts per million by weight and havea flexural modulus of about 1.20 GN/m².

The polymers obtained have a high molecular weight as indicated by themelt flow index measured according to the ASTM Test Method 1238 of 1970.Thus propylene polymers having a melt flow index of less than 200preferably less than 100 particularly less than 50 for example between 5and 50 may be obtained, the melt flow index being measured at atemperature of 190° C. and a weight of 10 kilograms.

Various aspects of the present invention will now be described withreference to the following Examples which are illustrative of theinvention. In all the Examples, unless otherwise stated, all operationswere effected in a nitrogen (British Oxygen Company--White Spot grade)atmosphere, and all the solvents and diluents used had been purged withnitrogen.

Preparation of Transition Metal π-Bonded Arene Complexes A. Preparationof Titanium Dichloride-Aluminum Chloride-Durene Complex

20 g of aluminum power (BDH fine powder) and 27 g of aluminum chloridewere introduced into a two liter flask. The mixture of solids wasstirred and heated to a temperature of 130° C., which temperature wasmaintained for two hours. The mixture was then cooled, and a solution of15.5 g of durene in one liter of toluene was added. The flask contentswere stirred and heated to reflux temperature. 19.9 g of titaniumtetrachloride in 100 ml of toluene were added dropwise over a period of30 minutes. Heating was continued, at reflux temperature, for a furtherhour and the mixture was then allowed to cool. The mixture was thenfiltered and the filtrate was allowed to run directly into 2.5 liters ofn-heptane. A dark-colored precipitate separated out and was filtered andthen washed four times with 250 ml of n-heptane for each wash. Theprecipitate was then dried under vacuum (0.2 mm pressure) at ambienttemperature (about 20° C.).

B. Preparation of Titanium(O)ditoluene

The procedure and apparatus used were as generally described in J. C. S.Chem. Comm. 1973, pages 866 and 867.

The apparatus is illustrated in the accompanying drawing. A glass flask1, the neck of which is tapered to provide a narrow portion 2, is alsoprovided with an outlet tube 3, the tube 3 being sealed with a groundglass end cap 4. A metal end block 5 is positioned at the end of theneck portion 2 of the flask 1. A sealing ring 6 is located within agroove in the bottom face of the block 5 and this sealing ring 6contacts the end (upper) face of the neck portion 2 to provide a sealbetween the flask 1 and the block 5. The block 5 is provided with a sidearm 7 which is connected to a vacuum pump (not shown).

Within the flask 1 is located an electron beam gun 8, a titanium billet9 and a shield 10. The whole of this assembly is mounted on an arm 11which contains high and low voltage leads and also circulating pipes forsupply and removal of cooling water. A tube 12 is also provided in theflask 1. The arm 11 and the tube 12 pass through the closed top end ofthe end block 5.

The bottom portion of the flask 1 is positioned within a refrigeratedbath 13 which contains liquid nitrogen 14. A motor (not shown) is alsoprovided to rotate the flask within the liquid nitrogen 14.

Using a 5 liter flask, titanium(O)ditoluene was prepared as follows.

The flask was evacuated to a pressure of 10⁻⁴ mm of mercury, immersed inthe liquid nitrogen 14 and rotated at 70 rpm. The titanium billet 9 wasapproximately 4 g in weight and the electron beam gun 8 was operated for3 hours at a power of 400 W (sufficient to evaporate about 0.8 g perhour of titanium). Toluene vapour was led into the flask at a rate ofabout 60 ml per hour through the tube 12, from the end of which thevapor was directed onto the inner surface of the flask on which itsolidified. The assembly of the gun 8, billet 9 and shield 10 waslocated to direct the evaporated titanium onto the solidified toluenewhere reaction occurred.

After 3 hours, evaporation of the titanium was stopped, the bath 13 wasremoved and argon was admitted to the flask whilst rotating the flask at30 rpm. Rotation of the flask was stopped, the end cap 4 removed and anargon purged Schlenk tube was placed on the outlet tube 3.

The flask was rotated at 30 rpm and allowed to warm up to ambienttemperature. The solid on the surface of the flask 1 melted and wasdischarged into the Schlenk tube. The liquid was deep red in color andcontained finely divided unreacted titanium which was allowed to settleand the clear red titanium(O)ditoluene solution was removed bydecantation. The product was stored at -78° C.

EXAMPLE 1

Into a stainless steel mill of 15.2 cm in length and 7.9 cm in diameter,and fitted internally with four metal strips, were introduced 200 steelballs of 12.7 mm diameter and 200 stainless steel balls of 6.35 mmdiameter. The mill was sealed, evacuated to 0.2 mm of mercury, andpurged with nitrogen to give a nitrogen atmosphere in the mill. 24.5 gof anhydrous magnesium chloride and 7.5 g of the product of PreparationA, were added to the mill which was then rotated at 120 rpm for fourdays. The temperature of the mill was controlled by continuouslyspraying water at 20° C. over the mill.

The contents of the mill were washed out with about 200 ml of n-heptaneand samples of the suspension were analysed for divalent titanium by theaddition of nitrogen purged 2 N sulphuric acid to an aliquot of thesample and thereafter titrating with ceric sulphate. The result of theanalysis for divalent titanium was confirmed by the addition of anexcess of acidified ferric sulphate to a further aliquot of the samplefollowed by titration of the ferrous sulphate thus formed with cericsulphate.

EXAMPLE 2

Into a Megapact Vibration Mill (manufactured by Pilamec,Gloucestershire, England) of internal diameter 3.8 cm and length 56 cm,were introduced 110 stainless steel balls of 12.7 mm diameter and 1700stainless steel balls of 6.35 mm diameter. The mill was sealed,evacuated to 0.2 mm of mercury and purged with nitrogen to give anitrogen atmosphere in the mill.

25.6 g of anhydrous magnesium chloride, 6.1 g of aluminum chloride and5.6 g of the product of Preparation A were mixed together in a reactionvessel by shaking under nitrogen and introduced into the mill undernitrogen. Water at 15° C. was circulated through the jacket of the mill.Milling was effected for a period of 18 hours using a frequency of 2800oscillations per minute and an amplitude of 2 mm. The contents of themill were washed out with about 200 ml of n-heptane. A sample of thematerial was obtained as a dry solid and was found to have a surfacearea of 5.95 m² /g.

EXAMPLE 3

The procedure of Example 2 was repeated using 29.0 g of anhydrousmagnesium chloride, 1.5 g of sodium chloride and 10.45 g of the productof Preparation A.

EXAMPLE 4

38.7 g of anhydrous magnesium chloride was milled for 60 hours using thevibration mill described in Example 2. The milled magnesium chloride waswashed out of the mill using 200 ml of toluene. A dry sample of themilled magnesium chloride was found to have a surface area of 44 m² /g.

To the stirred suspension of magnesium chloride in 200 ml of toluene wasadded a saturated solution in toluene of the product of Preparation A.The addition was continued until the supernatant liquid had a slight redtinge. The solid product was allowed to settle and the supernatantliquid decanted off. The solid was washed by filtration three times withtoluene (150 ml for each wash) and three times with n-heptane (150 mlfor each wash) and finally suspended in 200 ml of n-heptane.

EXAMPLE 5

The procedure of Example 2 was repeated using only 24.6 g of anhydrousmagnesium chloride and 7.4 g of the product of Preparation A.

To the suspension obtained from the mill was added 2 ml of titaniumtetrachloride, at ambient temperature (about 20° C.). The mixture wasimmediately filtered, washed 3 times with 200 ml of n-heptane andfinally resuspended in 200 ml of n-heptane.

EXAMPLES 6 TO 12

The products of Examples 1, 4 and 5 were used to polymerize propylene.

The propylene used for the polymerization had been purified by passinggaseous propylene in turn through a column (3 inches diameter, 3 feetlength) containing 1/16 inch granules of Alcoa F1 alumina at 50°-60° C.,and then through a similar column containing BTS catalyst (Cupric oxidereduced to finely divided metallic copper on a magnesium oxide support)at 40°-50° C., condensing the issue gas and passing the liquid propylenethrough four columns (all 3 inches diameter; two of 3 feet in length,two of 6 feet in length) at 25° C., each containing 1/16 inch pellets ofUnion Carbide 3A molecular sieves.

This treatment reduced the water content of the monomer from 5-10 ppm byvolume to <1 ppm by volume and the oxygen content from 1-2 ppm by volumeto <0.5 ppm by volume. The level of inert compounds (nitrogen, ethane,etc.) was unchanged at 0.3% and the level of unsaturated hydrocarbons(allene, methylacetylene, etc.) was unchanged at <1 ppm.

A polymerization flask equipped with efficient stirrer and a waterjacket was dried carefully and 1 liter of an inert hydrocarbon diluenthaving a boiling range of about 170°-180° C. was introduced. The diluentwas evacuated at 60° C., purged with nitrogen and evacuated whichtreatment effectively reduced the water and oxygen contents of thediluents to below 10 ppm by weight. The diluent was then saturated withthe purified propylene to one atmosphere pressure.

In some of the Examples (as indicated in Table 1), 8 millimoles oftriethyl aluminum were introduced. In the other Examples, 8 millimolesof triethyl aluminum, in 50 ml of the hydrocarbon diluent in a separateflask, were mixed, at 0° C., with 3 millimoles of ethyl anisate. Thismixture was then transferred immediately to the polymerization flask.Immediately after the addition of the triethyl aluminum, or mixturecontaining triethyl aluminum, a quantity of the product of one ofExamples 1, 4 or 5 was introduced. The pressure in the reaction vesselwas maintained at one atmosphere by supply of propylene from a burette.The run was terminated with 10 ml of isopropanol and 5 ml of propyleneoxide after a period of time indicated in Table 1, and a sample ofsupernatant liquid extracted for determining the concentration ofsoluble polymer dissolved in the polymerization diluent. The solid wasfiltered and the polymerization flask was washed with a minimum quantity(50 to 100 ml) of petrol ether, and the washings added to the filteredsolid. The solid was dried in a vacuum oven at 120° C. for an hour. Theyield of solid plus calculated soluble polymer equalled withinexperimental error the propylene loss from the burette.

The results obtained are set out in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                      % Weight of                                 Example              Polymerization                                                                        Yield                                                                              Diluent                                     or     Ti component                                                                           EA (b)                                                                             Time    of Solid                                                                           Soluble                                     Comparative                                                                          Type                                                                             Amount                                                                              Amount                                                                             (min)   Polymer                                                                            Polymer                                     Example                                                                              (a)                                                                              (mg atom)                                                                           (mM) (c)     (g)  (d)                                         __________________________________________________________________________    6      1  0.2   NIL  240     90   49                                          7      1  0.2   3.0  240     18    8                                          8      4  0.2   NIL  240     22.6 39                                          9      5  2.0   NIL   36     68   61                                          10     5  0.2   NIL  240     70   46                                          11     5  0.2   3.0  240     40   13                                          12     5  0.2   3.5  240     13    9                                          C      C  0.2   NIL  240     3.2  46                                          __________________________________________________________________________     Notes to Table 1                                                              (a) 1, 4 and 5 are the products of Examples 1, 4 and 5. C is the product      obtained by vibration milling 24.6 g of anhydrous magnesium chloride and      1.58 g of titanium dichloride as described in Example 2. The titanium         dichloride component was the product obtained by heating titanium             trichloride (prepared by hydrogen reduction of titanium tetrachloride)        under vacuum (less than 10.sup.-3 mm of mercury) at 475° C. for 18     hours to give a product having an analysis of TiCl.sub.2.08.                  (b) EA is ethyl anisate.                                                      (c) From time of adding the titanium component.                               (d) % based on total polymer (solid + soluble).                          

EXAMPLES 13 TO 19

The products of Examples 2 and 3 were used to effect polymerizationusing liquid propylene.

Polymerization was carried out in a stainless steel autoclave, of totalcapacity 8 liters, which was fitted with a water-circulation jacket anda vertical anchor stirrer. The autoclave was heated to 65° C.,evacuated, and the vacuum was released with propylene (purified as inExamples 6 to 12). The autoclave was then evacuated again and theprocedure repeated 5 times and the autoclave was finally brought to apressure of 2 psi gauge with propylene gas at 30° C. Approximately 50 mlof a heptane solution containing a mixture of triethyl aluminum andethyl anisate in the amounts indicated in Table 2 were added to theautoclave, followed by the product of Example 2 or Example 3. 5 litersof liquid propylene were added to the autoclave immediately after theaddition of the titanium-containing component, the stirrer beingoperated at 120 rpm. This propylene addition was effected by allowing5.5 liters of liquid propylene to transfer from a burette at 50° C. tothe autoclave. Hydrogen (250 gram millimoles) was added and thetemperature of the autoclave contents was raised to 65° C. over 10minutes. The hydrogen was commercially available hydrogen (99.99% pure)which had been further purified by passing through a column (8 inches by4 feet in length) containing a molecular sieve material (Union Carbide3A) at 20° C. The hydrogen was stored in the sieve column and drawn offas required. Polymerization was allowed to proceed at a temperature of65° C. and a pressure of 435 psi gauge. More hydrogen (48 grammillimoles on each occasion) was added every 30 minutes. After thedesired polymerization time, the autoclave was vented over a period of10 minutes to remove unpolymerized propylene, and a free-flowing powderwas obtained. The results obtained are set out in Table 2.

                                      TABLE 2                                     __________________________________________________________________________                            Polymer-                                                                      ization                                                                            Yield    Flexural                                Ti component  TEA (f)                                                                            EA (b)                                                                             Time of Solid                                                                           Found                                                                             Modulus                                      Type                                                                             Amount                                                                              Amount                                                                             Amount                                                                             (min)                                                                              Polymer                                                                            Ti  (g)                                     Example                                                                            (e)                                                                              (mg atom)                                                                           (mM) (mM) (c)  (g)  (ppm)                                                                             (GN/m.sup.2)                            __________________________________________________________________________    13   2  1.0   90   34   240  1410 32  1.11                                    14   2  1.0   60   24   240  1200 40  1.12                                    15   2  1.0   60   24    5    480 93  0.95                                    16   2  1.0   30   11   160  2170 23  0.92                                    17   2  0.5   30   11   240   470 53  1.11                                    18   2  1.0   15    6   120  1600 30  N.D.                                    19   3  1.0   90   34   240  1000 33  1.09                                    __________________________________________________________________________     Notes to Table 2                                                              (b) and (c) are as defined in Notes to Table 1.                               (e) 2 and 3 are the products of Examples 2 and 3.                             (f) TEA is triethyl aluminum.                                                 (g) The flexural modulus was measured using a cantilever beam apparatus a     described in Polymer Age, March 1970, pages 57 and 58. The deformation of     a test strip at 1% skin strain after 60 seconds at 23° C. and 50%      relative humidity was measured. The test strip had dimensions of              approximately 150 × 19 × 1.6 mm and was prepared as follows:      23 g of the polymer was mixed with 0.1% by weight of an antioxidant           (`Topanol` CA), and the mixture was added to a Brabender Plasticizer, at      190° C., 30 rpm and under a load of 10 kg to convert it to a crepe     The crepe was placed within a template, between aluminum foil, and presse     by means of an electric Tangye Press at a temperature of 250° C.       The pressing was preheated for a period of six minutes, under just enough     pressure to make the polymer flow across the template, that is an applied     force of about 1 ton. After the preheat period, the applied force was         raised to 15 tons in 5 ton increments, degassing (that is releasing           pressure) every 5 tons. After 2 minutes at 15 tons, the press was cooled      by means of air and water for 10 minutes or until room temperature was        reached. The plaque obtained was then cut into strips of dimensions 150       × 19 × 1.6 mm. Duplicate strips of each polymer were placed       into an annealing oven at 130° C., and after 2 hours at this           temperature the heat was switched off and the oven cooled to ambient          temperature at 15° C. per hour.                                   

EXAMPLE 20

Polymerization was carried out in a steel autoclave of capacity 8 litersfitted with an anchor stirrer/scraper. 400 grams of dry polypropylenewas added while stirring the autoclave at 70° C. The stirrer speed was120 rpm. The autoclave was evacuated, after half an hour the vacuum wasreleased with propylene, and then the autoclave was re-evacuated. Thisprocedure was repeated a further five times over an hour and a half toleave a slight excess pressure (2 psig) of propylene in the autoclave.The stirrer was stopped and a solution, in 50 ml of n-heptane, of 30millimoles triethyl aluminum and 11 millimoles of ethyl anisate wasinjected into the autoclave by means of a syringe. The autoclavecontents were stirred for 10 minutes, the stirrer was stopped and asuspension in heptane of the product of Example 1 was added in an amountsufficient to provide 0.31 milligram atom of titanium. The stirrer wasrestarted and propylene gas was then admitted to the top of theautoclave from a heated stock vessel containing liquid propylene. Apressure of 400 psi gauge was established over a period of about 30minutes. The temperature was maintained at 70° C. throughout. 80millimoles of hydrogen was added during the pressurization stage at arate of 20 millimoles for each 100 psig rise in propylene pressure.Polymerization was effected at 400 psig and 70° C., and hydrogen wasadded throughout the polymerization such that 10 millimoles of hydrogenwas added for every 200 ml of liquid propylene added from the stockvessel. After 4 hours polymerization, the propylene supply was switchedoff, and the autoclave vented to atmospheric pressure. The gas cap waspurged with nitrogen and the polymer emptied out. The polymer obtainedwas a free-flowing, greyish powder.

The initial charge of 400 g of polypropylene had the followingcharacteristics:

Titanium content: 43 ppm by weight

Melt flow index (measured by ASTM Test Method D 1238-70, Condition N,that is at 190° C. and 10 Kgm): 21

Flexural Modulus: 1.38 GN/m²

A total of 1245 g of polymer was obtained, that is 845 g of polymer wereformed during the polymerization period. The titanium content of thetotal polymer (initial charge plus polymer formed) was 26 ppm by weight.

EXAMPLE 21

100 ml of the solution of titanium(O)ditoluene obtained as described inPreparation B, after separation from the unreacted titanium, were addedslowly to 20 g of a stirred dry sample of magnesium chloride which hadbeen milled in a vibration mill as described in Example 2. When theaddition was complete, the mixture was stirred for 2 hours and thenallowed to settle. The color of the supernatant was pale pink. Themixture was filtered and the solid was resuspended in 100 ml ofn-heptane.

The suspension of the solid in n-heptane was stirred at ambienttemperature, 10 ml of titanium tetrachloride were added and the mixturewas stirred for one hour. The mixture was filtered and the solid waswashed, by filtration, 6 times with 100 ml of n-heptane each time, toremove the excess of titanium tetrachloride. The solid was finallysuspended in 100 ml of n-heptane.

EXAMPLES 22 TO 24

The contacting procedure of Example 21 was repeated using 45 g of milledmagnesium chloride and 150 ml of the titanum(O)ditoluene solution. Afterbeing resuspended in 300 ml of n-heptane, the mixture was separated intothree 100 ml portions.

One of the portions (Example 22) was given no further treatment.

Over one portion (Example 23) was passed anhydrous hydrogen chloride gasfor one hour, with stirring of the suspension. The suspension wasfiltered and the solid washed 5 times with 100 ml of n-heptane eachtime. The solid was finally resuspended in 100 ml of n-heptane.

The third portion (Example 24) was treated with 15 ml of titaniumtetrachloride, the procedure being as described in Example 21.

EXAMPLE 25

25 g of magnesium chloride were milled in a vibration mill as describedin Example 2. The milled magnesium chloride was contacted with 150 ml ofa toluene solution of titanium(O)ditoluene using the procedure ofExample 21. The product obtained was then treated with anhydroushydrogen chloride gas as described in Example 23.

EXAMPLE 26

25 g of anhydrous magnesium chloride were vibration milled, in thepresence of 3 ml of n-butyl chloride, using the milling procedure ofExample 2. The milled product, in the dry state, was then contacted witha toluene solution of titanium(O)ditoluene as in Example 21. On allowingthe mixture to settle, it was found that the supernatant liquid wasclear and water-white. The mixture was given no further treatment.

EXAMPLE 27

The procedure of Example 26 was repeated except that the magnesiumchloride was milled in the presence of 4 ml of toluoyl chloride.

EXAMPLES 28 TO 39

The polymerization procedure of Examples 6 to 12 was repeated using theproducts of Examples 21 to 27 in amounts sufficient to provide 0.2milligram atoms of titanium (estimated by treatment with sulphuric acidand titration with ceric sulphate as in Example 1). All polymerizationswere effected for four hours. The results obtained are set out in Table3.

                  TABLE 3                                                         ______________________________________                                                                          % Weight of                                                            Yield  Diluent                                            Ti component                                                                             EA (b)   of Solid                                                                             Soluble                                     Example                                                                              Type       Amount   Polymer                                                                              Polymer                                     (h)    (i)        (mM)     (g)    (d)                                         ______________________________________                                        28     21         NIL      17.5   26.9                                        29     21         3.0      5.0    4.8                                         30     22         NIL      1.0    38.5                                         31*   22         NIL      1.6    37.5                                        32     23         NIL      24.0   34.6                                        33     23         3.0      2.9    4.0                                         34     24         NIL      51.3   32.0                                        35     25         NIL      23.4   40.5                                        36     25         3.0      5.5    11.2                                        37     26         NIL      3.5    47.5                                        38     27         NIL      30.7   44.7                                        39     27         3.0      20.1   5.4                                         ______________________________________                                         Notes to Table 3                                                              (b) and (d) are as defined in Notes to Table 1.                               (h) In Example 31*, 0.6 mM of nbutyl chloride were added to the               polymerization mixture, after adding the aluminum triethyl but before         adding the titanium component.                                                (i) 21 to 27 are the products of Examples 21 to 27.                      

EXAMPLE 40

The procedure of Examples 13 to 19 was repeated using, as the catalystsystem, 0.22 milligram atoms of the product of Example 27, 20 millimolesof triethyl aluminum and 7.3 millimoles of ethyl anisate. Polymerizationwas terminated after one hour when a yield of 825 g of polypropylene wasobtained. The polymer was found to contain 16 ppm by weight of titaniumby X-ray fluorescence spectrometry. The flexural modulus of the polymerwas 1.20 GN/m².

EXAMPLE 41

A 3 liter autoclave was charged with 2 liters of hexane and 1.0 g ofalumina (Ketjen Grade B alumina dried under nitrogen at 500° C. for 2hours). Purified ethylene was added to raise the pressure to 75 psig,and the autoclave was depressurized to atmospheric pressure. A solutioncontaining 0.15 millimoles of titanium(O)ditoluene (obtained by theprocedure of Preparation B) was added and ethylene readmitted to give apressure of 75 psig. An initial exotherm raised the temperature from 70°C. to 80° C., which latter temperature was maintained for a period of 1hour, during which time ethylene was continuously admitted to theautoclave to maintain the pressure at 75 psig. 600 g of high molecularweight polyethylene, insoluble in the diluent, was obtained which, onbeing dried, gave a free-flowing white powder.

EXAMPLE 42

The procedure of Example 41 was repeated except that the alumina wascontacted with the titanium compound in a separate vessel in the absenceof ethylene. The contacting was effected at 0° C. by the addition of thetoluene solution of the titanium(O)ditoluene to a hexane suspension ofthe alumina. The color of the titanium compound was discharged from thesolution affording a clear, water-white supernatant liquid. The mixturethus produced was introduced into the autoclave when the ethylenepressure was atmospheric pressure. A similar yield of polymer wasobtained as in Example 41.

COMPARATIVE EXAMPLE D

The procedure of Example 41 was repeated except that the alumina wasabsent. No exotherm was observed, and only 0.4 g of a white solid wasproduced.

EXAMPLE 43

A 1 liter autoclave was charged with hexane (500 ml) and alumina (1.0g), heated to 35° C. and pressurized with purified propylene to give atotal pressure of 150 psig. Titanium(O)ditoluene (0.3 mmol) in toluenewas admitted. The autoclave was maintained at 35° C. for a period of onehour with continuous admission of propylene to maintain the pressure at150 psig. 35 g of polypropylene was obtained. This consisted of adiluent insoluble portion (51%) which was principally isotactic materialand was obtained as a free-flowing white powder, and a diluent solubleportion (49%) which was principally atactic material.

EXAMPLE 44

The polymerization procedure of Example 41 was repeated using adifferent catalyst system which was introduced when the ethylenepressure was atmospheric pressure. The catalyst was 8 millimoles oftriethyl aluminum followed by the product of Example 1 in a quantitysufficient to provide 0.2 milligram atoms of titanium. Polymerizationwas continued for 2.5 hours at 80° C. and a total pressure of 75 psigusing a flow rate of 300 liters per hour of ethylene and 100 liter perhour of hydrogen gas. 450 g of polyethylene, having a melt flow index(measured at 190° C. with a 2.16 kg weight) of greater than 100, wasobtained.

EXAMPLE 45

The procedure of Example 44 was repeated using 4 millimoles of triethylaluminum and sufficient of the titanium compound to provide 0.1milligram atoms of titanium. Polymerization was continued for 3 hours at80° C. and a total pressure of 75 psig using 370 liters per hour ofethylene and 30 liters per hour of hydrogen. 500 g of polyethylene, ofmelt flow index 25, was obtained.

EXAMPLE 46

To a suspension, in 100 ml of n-heptane, of 20 g of alumina of the typeused in Example 41 was added 150 ml of a solution in toluene oftitanium(O)ditoluene prepared as described in Preparation B. Oncompletion of the addition of the solution of the titanium compound, thesupernatant liquid was clear and water-white.

8 ml of the suspension thus obtained (containing about 0.2 milligramatoms of titanium) were added, at ambient temperature, to a steelautoclave of 60 ml capacity which was fitted with a stirrer. Theautoclave was cooled in liquid nitrogen and 20 ml of butadiene weredistilled into the autoclave, which was allowed to warm up to ambienttemperature and then rapidly heated to 65° C. whilst stirring thecontents of the autoclave. After one hour at 65° C., with stirring, theautoclave was cooled and the excess, unreacted butadiene was vented off.9 g of polybutadiene were obtained.

EXAMPLE 47

The procedure of Example 44 was repeated using 8 millimoles of aluminumtriethyl and sufficient of the titanium compound to provide 0.2milligram atoms of titanium. 125 ml of hexene-1 were added initially andthe ethylene was passed into the reaction vessel at a low rate of 300liters per hour and at a total pressure of 75 psi gauge and a further 40ml of hexene-1 were added during the polymerization. After 2 hourspolymerization, 350 g of an ethylene/hexene-1 copolymer was obtainedwhich had a melt flow index of 2.5, a hexene-1 incorporation of 6.6%molar and a density of less than 0.94 g/cm³.

EXAMPLE 48

The procedure of Example 47 was repeated except that there was noinitial quantity of hexene-1, and 60 ml of hexene-1 was added during thecourse of the polymerization. A yield of 530 g was obtained and theproduct had a melt flow index of 0.002, a hexene-1 incorporation of 0.9%molar and a density of between 0.94 and 0.95 g/cm³.

EXAMPLES 49 TO 59

Several samples of titanium(O)ditoluene were prepared by the procedureof Preparation B, and these were then supported on alumina. Thetitanium(O)ditoluene was stored at -78° C. using a methanol/solid carbondioxide mixture. The solution of the titanium compound was added to 20 gof alumina (Grade B alumina dried under nitrogen at 500° C. for 2 hours)at -78° C., the mixture was stirred for two hours, allowed to warm up toroom temperature and then allowed to settle.

The supported product was then used to polymerize propylene in anautoclave of 5 liters nominal capacity.

Three liters of the hydrocarbon diluent used in Examples 6 to 12 wereintroduced into the autoclave and heated up to the polymerizationtemperature. In some of the polymerizations, a quantity of anorgano-aluminum compound was added. The supported titanium compound wasthen added in a quantity sufficient to provide 2 milligram atoms oftitanium. In some examples, hydrogen was then added. Finally, propylenewas added in a sufficient quantity to raise the pressure to 100 psigauge. Polymerization was continued for four hours, the pressure beingmaintained at 100 psi gauge by the addition of propylene and, in thoseexample in which hydrogen was used, intermittent additions of hydrogenwere also made.

At the end of the four hour polymerization period, the autoclave wasvented, nitrogen was introduced to give a slight excess pressure (about2 psi gauge) and the polymer suspension was run out of the autoclave. Asmall aliquot of the polymer suspension was collected and allowed tosettle to determine by evaporation the proportion of diluent solublepolymer formed. The major portion of the polymer suspension wasfiltered, the polymer was washed with petroleum ether and then dried ina vacuum oven at 100° C. and 15 mm pressure for 24 hours.

Further details of the polymerization conditions, and the yield of solidand soluble polymer obtained are set out in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                      H.sub.2 Amount                                                                        Yield  Proportion                                    Activator        (% by volume                                                                          of Solid                                                                             of diluent                                   Example                                                                            Type                                                                              Amount                                                                             Temp                                                                              relative to                                                                           Polymer                                                                              soluble                                      No.  (f) (j)                                                                           (mM) (°C.)                                                                      propylene)                                                                            (g/mM of Ti)                                                                         Polymer (%)                                  __________________________________________________________________________    49   NIL --   60  NIL     72*    1.23**                                       50   NIL --   100***                                                                            NIL     >30    N.D.                                         51   NIL --   70  NIL     40     0.86                                         52   TEA 10   60  NIL     16     N.D.                                         53   TEA 2    70  NIL     30     N.D.                                         54   DEAC                                                                              2    70  NIL     65.6   N.D.                                         55   NIL --   60  0.1     115.sup.+                                                                            1.34                                         56   NIL --   60  1.0     64     2.8                                          57   NIL --   70  1.0     65.sup.++                                                                            2.83                                         58.sup.+++                                                                         NIL --   70  NIL     49     N.D.                                         59°                                                                         TEA 2    70  NIL     ˜5                                                                             N.D.                                         __________________________________________________________________________     Notes to Table 4                                                              (f) is as defined in Notes to Table 2                                         (j) DEAC is diethyl aluminum chloride                                         *Average of four results                                                      **Average of three results                                                    ***Cooled to 60° C. and then vented                                    .sup.+ This result is believed to be too high, due to the presence of         diluent trapped in the polymer particles                                      .sup.++ Average of two results                                                .sup.+++ Support was a SiO.sub.2 /Al.sub.2 O.sub.3 powder (Ketjen Grade       5P, dried at 500° C. for 2 hours under N.sub.2)                        °A sample of the catalyst used in Example 58 was stirred for 15        minutes with an equimolar proportion of TiCl.sub.4 (as a solution of          TiCl.sub.4 in heptane), the solid was allowed to settle and the               supernatant liquid was removed.                                          

The polymer product obtained in all the examples appeared similar and aseries of tests was carried out on the product of one of the runsforming example 49. The results of the tests are set out in Table 5.

                  TABLE 5                                                         ______________________________________                                        Test                  Result                                                  ______________________________________                                        Melt flow index (ASTM Test Method                                             D 1238-70)                                                                    Determined at 190° C. and 10 kg                                                              <0.01                                                   Determined at 230° C. and 10 kg                                                              0.08                                                    Head-to-head units (k)                                                                              about 4 per 100                                         (infrared spectroscopy)                                                                             propylene units                                         (13Cnmr)                                                                      Isotactic polymer (l) 80%                                                     Racemic diads (m)     9.3%                                                    Elongation (n)        >1000%                                                  Glass Transition temperature (p)                                                                    <-10° C.                                         Low temperature brittle point (q)                                                                   -26° C.                                          ______________________________________                                         Notes to Table 5                                                              (k) Determined from an absorption band at 752 cm.sup.-1 in the infrared       spectrum and chemical shifts of 16.9, 17.3, 31.0, 34.5, 35.5 and 38.3 ppm     by 13Cnmr relative to tetramethyl silane.                                     (l) Determined from the triads which are mm centered by C13nmr of the         α-methyl resonance.                                                     (m) Determined using 100 MHz proton nmr. The results are expressed as %       racemic units, that is the number of r units (specifically as mrm or rrr)     per 100 repeat units in the polymer.                                          (n) Determined using Instron Testing Machine at 20° C. using a         crosshead speed of 5 mm/minute up to 100% elongation, and 50 mm/minute        above 100% elongation. The samples used were strips measuring 5 cm .times     1 cm × 1 mm cut from a 1 mm thick sheet compression molded at 20        tons per square inch and 215° C., quenched in cold water and then      annealed by placing in an oven between glass plates at 100° for 4      hours and allowing to cool to room temperature overnight. At 1000%            elongation, the apparent stress was 17.5 MN/m.sup.2 and the specimen did      not break. On releasing the stress, the specimen contracted to an             elongation of 200%.                                                           (p) Measured using a torsional pendulum following the procedure of I.S.O.     Recommended method R 537 (Procedure B).                                       (q) Performed using an apparatus constructed in accordance with and using     the procedure of I.S.O. Recommended method R 974.                        

In a polymerization carried out using the conditions of Example 49 and atemperature of 20° C., a negligible yield of solid polymer was obtained.

In a further polymerization effected using a catalyst supported onsilica, and a polymerization temperature of 70° C., a negligible yieldof solid polymer was obtained. A similar effect was obtained using acatalyst supported on chlorinated alumina. Similar effects were alsoobtained using unsupported titanium(O)ditoluene as the catalyst andunsupported titanium(O)ditoluene which had been degraded by standing atambient temperature for 24 hours.

EXAMPLES 60 AND 61

Polymerization was effected in the gas phase using titanium(O)ditoluenesupported on alumina and prepared as described for Examples 49 to 59.

40 gms of dry polypropylene powder was stirred in a 2 liter glass flaskfitted with an anchor stirrer formed from polytetrafluoroethylene. Awater jacket kept the flask at the required temperature. The flask wasevacuated to 1.0 mm of Hg and then pressurized to atmospheric pressurewith dry nitrogen to remove air and moisture from the apparatus. Thiswas repeated twice more. The evacuation and pressurization procedure wasthen effected three times with propylene containing the proportion ofhydrogen specified in Table 6.

After the addition of the catalyst system, (containing 2 milligram atomsof titanium) propylene, containing hydrogen as specified, was addedcontinuously from a metering device so as to maintain the pressurewithin the apparatus at atmospheric pressure. Polymerization was allowedto continue for the time indicated in Table 6, this being measured fromthe time that the titanium containing material was introduced. The totalproduct was then removed from the apparatus and dried.

                  TABLE 6                                                         ______________________________________                                        Ex-  Hydrogen Amount                                                          am-  (% by volume                   Yield of Solid                            ple  relative to   Temperature                                                                              Time  Polymer                                   No.  propylene)    (°C.)                                                                             (hours)                                                                             (g/mM of Ti)                              ______________________________________                                        60   NIL           65         4.0 (r)                                                                             5                                         61 (s)                                                                             0.1           40-60 (t)  6.0   6                                         ______________________________________                                         Notes to Table 6                                                              (r) Pressure reduced to 1.0 mm of Hg for 5 minutes after 3 hours              polymerization, this did not effect the polymerization rate.                  (s) In this experiment, no carrier polymer was used.                          (t) The initial temperature was 40° C. and was raised to 60.degree     C. after 1.5 hours.                                                      

Further experiments were carried out at 40° C. in the presence oforgano-aluminum compound (triethyl aluminum or diethyl aluminumchloride) but negligible quantities of polymer product were obtainedunder these conditions.

C. Preparation of a toluene solution titanium dichloride-aluminumchloride-toluene complex

This complex was prepared in a manner similar to Preparation A, using 24g aluminum powder, 32.4 g of aluminum chloride. 24.2 g of titaniumtetrachloride and 1 liter toluene. The mixture was refluxed for 8 hours,cooled to 0° C. for 2 hours and then filtered, to yield a solution whichwas 0.0503 molar.

EXAMPLE 62

6.8 g of alumina (Ketjen, Grade B, dried under nitrogen at 500° C. for 2hours) were slurried in 136 ml dried heptane (that is 20 ml heptane foreach gram of Al₂ O₃). 19.9 ml of the toluene solution from Preparation Cwere added to 20 ml of the stirred slurry of Al₂ O₃ to yield a productcontaining 1 mM titanium complex adsorbed on 1 g Al₂ O₃. The productprepared as described was used in a sufficient quantity to provide onemilligram atom of titanium to polymerize propylene at 60°. Thepolymerization technique was as described in Examples 6 to 12. After 1hour, 1.8 g of a solid, insoluble polymer was obtained.

We claim:
 1. A process for the production of a hydrocarbon polymerwherein at least one ethylenically unsaturated hydrocarbon monomer iscontacted with a polymerization catalyst which contains a compound of atransition metal, other than zirconium, of Group IVA of the PeriodicTable, wherein the said compound contains at least one π-bonded arenegroup, and is supported on a particulate inorganic compound which is (A)an inorganic oxide, an inorganic hydroxide, an inorganic oxyhalide, aninorganic hydroxyhalide or an inorganic halide; (B) a mixture of atleast two compounds from (A); or (C) a compound obtained by the reactionof at least two compounds from (A).
 2. A process for the production of ahydrocarbon polymer wherein at least one ethylenically unsaturatedhydrocarbon monomer is contacted with a polymerization catalyst whichcontains a compound of titanium, wherein the said compound contains atleast one π-bonded arene group, and is supported on a particulateinorganic compound which is (A) an inorganic oxide, an inorganichydroxide, an inorganic oxyhalide, an inorganic hydroxyhalide or aninorganic halide; (B) a mixture of at least two compounds from (A); or(C) a compound obtained by the reaction of at least two compounds from(A).
 3. The process of claim 1 or claim 2 wherein the catalyst containsa titanium dichloride-aluminum chloride-arene complex supported onmagnesium chloride or alumina.
 4. The process of claim 1 or claim 2wherein the catalyst contains a titanium dichloride-aluminumchloride-arene complex supported on magnesium chloride admixed withaluminum chloride or sodium chloride.
 5. The process of claim 1 or claim2 wherein the catalyst contains a titanium dichloride-aluminumchloride-arene complex supported on magnesium chloride and treated withtitanium tetrachloride.
 6. The process of claim 1 or claim 2 wherein thecatalyst contains titanium(O)ditoluene supported on magnesium chloride.7. The process of claim 1 or claim 2 wherein the catalyst containstitanium(O)ditoluene supported on alumina.
 8. The process of claim 1 orclaim 2 wherein the catalyst contains titanium(O)ditoluene supported onmagnesium chloride and treated with titanium tetrachloride or hydrogenchloride.
 9. The process of claim 1 or claim 2 wherein the catalystcontains titanium(O)ditoluene supported on magnesium chloride which hasbeen treated with butyl chloride or toluoyl chloride.
 10. The process ofclaim 7 wherein ethylene is polymerized.
 11. The process of claim 3wherein propylene is polymerized.
 12. The process of claim 7 whereinpropylene is polymerized.
 13. The process of claim 1 or claim 2 whereinthe polymerization catalyst also includes at least one organo-metalliccompound of aluminum or of a non-transition metal of Group IIA of thePeriodic Table or a complex of an organo-metallic compound of anon-transition metal of Groups IA or IIA of the Periodic Table and anorganic aluminum compound.
 14. The process of claim 13 wherein thepolymerization catalyst also contains an organic-Lewis Base compoundwhich is an aromatic ester.
 15. A process for the production of apropylene polymer wherein propylene is contacted with a polymerizationcatalyst comprising a transition metal component, an organo-aluminumcompound and an organo-Lewis Base compound wherein the transition metalcomponent is a compound of a transition metal of Group IVA of thePeriodic Table, which compound contains at least one π-bonded arenegroup, and which is supported on a particulate inorganic halide.
 16. Theprocess of claim 15 wherein the transition metal component is eithertitanium(O)ditoluene, or a titanium dichloride-aluminum chloride-arenecomplex, supported on magnesium chloride.
 17. The process of claim 15wherein the organo-aluminum compound is aluminum triethyl and the LewisBase is an aromatic ester.
 18. A process for the production of ahydrocarbon polymer wherein at least one ethylenically unsaturatedhydrocarbon monomer is contacted with a polymerization catalyst whichcontains a titanium dichloride-aluminum chloride-arene complex supportedon a particulate inorganic compound which is (A) an inorganic oxide, aninorganic hydroxide, an inorganic oxyhalide, an inorganic hydroxyhalideor an inorganic halide; (B) a mixture of at least two compounds from(A); or (C) a compound obtained by the reaction of at least twocompounds from (A).
 19. A solid polypropylene polymer having a melt flowindex (measured at 190° C. using a 10 kg weight) of not greater than0.02, and containing at least three head-to-head units for each 100propylene units.
 20. The polymer of claim 19 which has a melt flow indexof less than 0.01 and contains at least four head-to-head units for each100 propylene units.
 21. The polymer of claim 19 which has an isotacticcontent of at least 70%.
 22. The polymer of claim 19 which has aproportion of at least 5% of racemic diads.
 23. The polymer of claim 19which has a glass transition temperature of below 0° C.
 24. The polymerof claim 19 which has a low temperature brittle point which is below-20° C.